CODEWITHSUNDEEP
javainner-classes
Hani Goc
Hani Goc

Reputation: 2441

Object instantiation: Inner class and outer class with the same name (Java)

Code description and ouput

In the following code. We have a class TestInners, one inner class A, one method local inner class A and one outer class A.

  1. When we instantiate an object as in new A().m(); the ouput is middle.
  2. In order for the program to output inner we must instantiate the object after the method local inner class A in the gomethod.
  3. If we comment the inner class the program will output outer.

Question

In the code as it is. Why did it output middle? Is there a preference for the inner classes first? then the outer classes? I got confused.

Source code

   class A { void m() { System.out.println("outer"); } }
    
    public class TestInners {
        public static void main(String[] args) {
            new TestInners().go();
        }
        void go() {
            new A().m();
            class A { void m() { System.out.println("inner"); } }
            
        }
        class A { void m() { System.out.println("middle"); } }
    }

Upvotes: 1

Views: 621

Answers (1)

Thilo
Thilo

Reputation: 262534

Yes, if you shadow symbols with more local definitions, the more local one is chosen. This most frequently happens with method parameters vs instance fields, leading to the famous this.name = name idiom.

In your case, you can get to the outer class by using a fully qualified class name.

But don't name classes like that. Too much confusion for no reason.

Upvotes: 5

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